jQuery.extend({
  createUploadIframe: function(id, uri)
 {
  //create frame
var frameId = 'jUploadFrame' + id;
if(window.ActiveXObject) {
var io = document.createElement('<iframe id="' + frameId + '" name="' + frameId + '" />');
if(typeof uri== 'boolean'){
io.src = 'javascript:false';
}
else if(typeof uri== 'string'){
io.src = uri;
}
}
else {
var io = document.createElement('iframe');
io.id = frameId;
io.name = frameId;
}
io.style.position = 'absolute';
io.style.top = '-1000px';
io.style.left = '-1000px'; 
 
document.body.appendChild(io); 
 
return io  
  },
  createUploadForm: function(id, fileElementId)
 {
 //create form 
 var formId = 'jUploadForm' + id;
 var fileId = 'jUploadFile' + id;
 var form = $('<form action="" method="POST" name="' + formId + '" id="' + formId + '" enctype="multipart/form-data"></form>'); 
 var oldElement = $('#' + fileElementId);
 var newElement = $(oldElement).clone();
 $(oldElement).attr('id', fileId);
 $(oldElement).before(newElement);
 $(oldElement).appendTo(form);
 //set attributes
 $(form).css('position', 'absolute');
 $(form).css('top', '-1200px');
 $(form).css('left', '-1200px');
 $(form).appendTo('body'); 
 return form;
  },
 addOtherRequestsToForm: function(form,data)
 {
 // add extra parameter
 var originalElement = $('<input type="hidden" name="" value="">');
 for (var key in data) {
  name = key;
  value = data[key];
  var cloneElement = originalElement.clone();
  cloneElement.attr({'name':name,'value':value});
  $(cloneElement).appendTo(form);
 }
 return form;
 }, 
 
  ajaxFileUpload: function(s) {
    // TODO introduce global settings, allowing the client to modify them for all requests, not only timeout 
    s = jQuery.extend({}, jQuery.ajaxSettings, s);
    var id = new Date().getTime()    
 var form = jQuery.createUploadForm(id, s.fileElementId);
 if ( s.data ) form = jQuery.addOtherRequestsToForm(form,s.data);
 var io = jQuery.createUploadIframe(id, s.secureuri);
 var frameId = 'jUploadFrame' + id;
 var formId = 'jUploadForm' + id; 
    // Watch for a new set of requests
    if ( s.global && ! jQuery.active++ )
 {
  jQuery.event.trigger( "ajaxStart" );
 }      
    var requestDone = false;
    // Create the request object
    var xml = {} 
    if ( s.global )
jQuery.event.trigger("ajaxSend", [xml, s]);
    // Wait for a response to come back
    var uploadCallback = function(isTimeout)
 {  
  var io = document.getElementById(frameId);
try
  {  
  if(io.contentWindow)
  {
   xml.responseText = io.contentWindow.document.body?io.contentWindow.document.body.innerHTML:null;
 xml.responseXML = io.contentWindow.document.XMLDocument?io.contentWindow.document.XMLDocument:io.contentWindow.document;
  }else if(io.contentDocument)
  {
   xml.responseText = io.contentDocument.document.body?io.contentDocument.document.body.innerHTML:null;
 xml.responseXML = io.contentDocument.document.XMLDocument?io.contentDocument.document.XMLDocument:io.contentDocument.document;
  }   
}catch(e)
  {
  jQuery.handleError(s, xml, null, e);
  }
if ( xml || isTimeout == "timeout")
  {  
requestDone = true;
var status;
try {
status = isTimeout != "timeout" ? "success" : "error";
// Make sure that the request was successful or notmodified
if ( status != "error" )
   {
// process the data (runs the xml through httpData regardless of callback)
var data = jQuery.uploadHttpData( xml, s.dataType );  
// If a local callback was specified, fire it and pass it the data
if ( s.success )
s.success( data, status );
// Fire the global callback
if( s.global )
jQuery.event.trigger( "ajaxSuccess", [xml, s] );
} else
jQuery.handleError(s, xml, status);
} catch(e)
  {
status = "error";
jQuery.handleError(s, xml, status, e);
} 
 
// The request was completed
if( s.global )
jQuery.event.trigger( "ajaxComplete", [xml, s] ); 
 
// Handle the global AJAX counter
if ( s.global && ! --jQuery.active )
jQuery.event.trigger( "ajaxStop" ); 
 
// Process result
if ( s.complete )
s.complete(xml, status); 
 
jQuery(io).unbind() 
 
setTimeout(function()
     { try
     {
      $(io).remove();
      $(form).remove(); 
     } catch(e)
     {
      jQuery.handleError(s, xml, null, e);
     }     
 
     }, 100) 
 
xml = null
 
}
    }
    // Timeout checker
    if ( s.timeout > 0 )
 {
setTimeout(function(){
// Check to see if the request is still happening
if( !requestDone ) uploadCallback( "timeout" );
}, s.timeout);
    }
    try
 {
      // var io = $('#' + frameId);
  var form = $('#' + formId);
  $(form).attr('action', s.url);
  $(form).attr('method', 'POST');
  $(form).attr('target', frameId);
if(form.encoding)
  {
form.encoding = 'multipart/form-data';  
}
else
  {  
form.enctype = 'multipart/form-data';
}  
$(form).submit(); 
 
    } catch(e)
 {  
jQuery.handleError(s, xml, null, e);
    }
if(window.attachEvent){
document.getElementById(frameId).attachEvent('onload', uploadCallback);
    }
    else{
document.getElementById(frameId).addEventListener('load', uploadCallback, false);
    }  
    return {abort: function () {}}; 
 
  }, 
 
  uploadHttpData: function( r, type ) {
    var data = !type;
    data = type == "xml" || data ? r.responseXML : r.responseText;
    // If the type is "script", eval it in global context
    if ( type == "script" )
jQuery.globalEval( data );
    // Get the JavaScript object, if JSON is used.
    if ( type == "json" )
eval( "data = " + data );
    // evaluate scripts within html
    if ( type == "html" )
jQuery("<div>").html(data).evalScripts();
  //alert($('param', data).each(function(){alert($(this).attr('value'));}));
    return data;
  }
})